Thanks @initall looks like I just need the same code on both, with the same value for '_setDomainName' and true for '_setAllowLinker' ?
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Jake NJan 29 '13 at 11:36

You can relax to only _setDomainName('.example.com'). The _setAllowLinker is just for the examples where they link to and between different toplevel domains, as the cookie information (which is what setDomainName sets) is otherwise lost.
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initallJan 29 '13 at 11:54